Interventions to Promote Handwashing

This is an interim intervention report. We have spent limited time to form an initial view of this program and, at this point, our views are preliminary. We may consider undertaking additional work on this program in the future.


  • What is the program? A range of behavioral interventions to promote handwashing through education and/or provision of materials.
  • What is its evidence of effectiveness? A Cochrane meta-analysis of randomized controlled trials (RCTs) indicates that interventions to promote handwashing cause a ~30% reduction in diarrhea incidence in children under the age of 5, but the programs evaluated and the effect sizes vary. One RCT indicates that a handwashing intervention caused a ~50% reduction of pneumonia in children under the age of 5 in Pakistan. We have not found strong evidence that promotion of handwashing reduces worm infections or improves nutrition indicators such as weight-for-age or weight-for-height.
  • How cost-effective is it? Our best guess is that handwashing promotion is below the range of cost-effectiveness of programs we would consider directing funding to. The assumptions informing our cost-effectiveness estimate for this intervention are likely to vary widely between different programs (more so than for other interim cost-effectiveness analyses we have done).
  • Does it have room for more funding? We have not yet completed a review of funding opportunities for interventions to promote handwashing.
  • Bottom line: Our current best guess is that handwashing promotion is less cost-effective than programs we would consider directing funding to. We may revisit this intervention if we find an organization which could answer our questions for charities.

Published: June 2017; Last updated: March 2021 (2017 version)

Table of Contents

What is the problem?

Lack of handwashing can increase transmission of infectious diseases, including diarrheal disease and pneumonia.1 According to the World Health Organization, approximately 525,000 children under the age of five die as a result of diarrheal disease each year,2 and approximately 920,000 children under the age of 5 died from pneumonia in 2015.3

What is the program?

Washing hands removes the pathogens which transmit diarrhea and other diseases.4 A range of behavioral interventions can be used to promote handwashing, including hygiene education (delivered individually or in groups) and distribution of posters and leaflets.5 Promotion of handwashing is often combined with other hygiene-promoting activities.6 Soap is sometimes provided as part of the intervention.7

This page focuses on interventions to promote handwashing in schools, day-care centers, or in the community. Handwashing can also be promoted in hospitals, or through mass media campaigns.8

Does the program have strong evidence of effectiveness?

We have searched for randomized controlled trials (RCTs) of the effectiveness of handwashing interventions on reducing diarrhea, pneumonia and worm infections and on improving nutrition.

  • There are twelve RCTs of handwashing programs on diarrhea in low- and middle-income countries (LMICs).9 The programs vary in their approach and intensity.10 A Cochrane meta-analysis finds a ~30% reduction in diarrhea incidence in children under the age of 5.11 We have not looked closely at all the trials in this review.
  • One RCT focused on pneumonia in an LMIC. It finds a ~50% reduction in pneumonia incidence.12
  • A Cochrane review found no effect of handwashing on nutrition.13
  • There are two RCTs on the effect of handwashing promotion on worm infections.14 One found a statistically significant reduction in incidence of worm infections, but no difference in intensity of infections. The other found a statistically significant reduction in intensity of infections, but no reduction in incidence.15

We note that:

  • Trials which blinded the outcome assessor found smaller (but still statistically significant) effects.16
  • Participants were not blinded in any of the studies,17 meaning they knew if they were in the treatment or control group. We believe this may have influenced the accuracy of reported histories of diarrhea. In a separate Cochrane review of water quality interventions (Clasen et al. 2007), unblinded studies found statistically significant reductions in diarrhea prevalence, while blinded studies did not. We discuss this review in detail in our water quality intervention report.
  • Only one of the trials was in Africa, the region in which we would guess a charity we review would most likely be based.18 It found a small reduction in diarrhea incidence, which was not statistically significant.19
  • Monitoring of diarrhea incidence occurred between every two weeks and daily in the trials.20 It is possible that monitoring alone would have improved handwashing compliance.21 A program implemented by a charity we review may have less intense monitoring.
  • The only RCT which studied pneumonia (finding a ~50% reduction) was of the same intervention as the RCT which found the largest reduction in diarrhea.22 If this intervention was unusually effective by chance, we would expect programs run by other charities to have a lower impact on pneumonia. On the other hand, if there are identifiable features of this intervention which made it particularly effective, we would expect other programs which shared these features to be more effective than a typical handwashing program.

Because of these issues in the evidence and the variety of approaches, we have not seen compelling evidence that handwashing programs, in general, should be considered a priority program. We are uncertain whether charities implementing particularly effective handwashing programs would be as cost-effective as our current top charities. If a charity focused on handwashing applied to be a top charity, we would focus on the questions below.

How cost-effective is it?

Based on a cost-effectiveness model we put together in May 2017 and updated with our most recent moral weights as of February 2021, we estimate that handwashing promotion is below the range of cost-effectiveness of the opportunities that we expect to direct marginal donations to (about 10x cash or higher, as of 2021).23

Note that our cost-effectiveness analyses are simplified models that do not take into account a number of factors. There are limitations to this kind of cost-effectiveness analysis, and we believe that cost-effectiveness estimates such as these should not be taken literally, due to the significant uncertainty around them. We provide these estimates (a) for comparative purposes and (b) because working on them helps us ensure that we are thinking through as many of the relevant issues as possible.

Does the program have room for more funding?

We have not yet completed a review of the funding landscape for interventions to promote handwashing.

Focus of further investigation

We do not currently consider behavioral interventions to promote handwashing to be a priority program. However, our cost-effectiveness estimate is sensitive to a number of assumptions which are likely to vary between charities. We would consider revisiting this intervention if we found a funding opportunity which could answer our questions for a charity.

We also plan to revisit this intervention when the results of the WASH benefits trial are released.

Questions for a charity

  • What is your cost per person?
  • What is the incidence of diarrhea and pneumonia in the populations you serve?
  • Of the population you serve, what proportion is children under the age of five?
  • How does the intervention you implement compare to the RCTs reviewed on this page?

Other remaining questions

  • Does a reduction in diarrhea and pneumonia incidence result in proportionally fewer deaths?
  • For how long does handwashing behavior change, i.e., does a reduction in disease incidence continue after the intervention?

Our process

We searched the Cochrane database for systematic reviews of the effectiveness of handwashing on reducing incidence of diarrhea and nutrition status. We used a Google Scholar search to identify systematic reviews of the effectiveness of handwashing interventions on reducing worm infections and incidence of pneumonia. Where the results of a particular study (e.g. Luby et al. 2004, Luby et al. 2005, Luby et al. 2006, Luby et al. 2009) were particularly relevant to our view, we have vetted that study. We have not vetted the other studies in the systematic reviews to the same level as we would for a full intervention report.


Document Source
Al-Delaimy et al. 2014 Source (archive)
Bieri et al. 2013 Source (archive)
Carabin et al. 1999 Source (archive)
CDC Fact Sheet - Diarrheal disease Source (archive)
Clasen et al. 2007 Source (archive)
Dangour et al. 2013 Source (archive)
Ejemot-Nwadiaro et al. 2015 Source (archive)
GiveWell, Cost-effectiveness analysis, 2020, Version 2 Source
GiveWell, Handwashing CEA, 2021 Source
GiveWell, Handwashing promotion moral weights, 2021 Source
Global Scaling Up Handwashing Project 2012 Source (archive)
Gyorkos et al. 2013 Source (archive)
Haggerty et al. 1988 Source (archive)
Institute for Health Metrics and Evaluation, Global Burden of Disease, GBD Compare, Under 5 deaths due to diarrhea, sub-Saharan Africa (accessed February 9, 2021) Source (archive)
Institute for Health Metrics and Evaluation, Global Burden of Disease, GBD Compare, Under 5 deaths due to lower respiratory infections, sub-Saharan Africa (accessed February 9, 2021) Source (archive)
Jefferson et al. 2011 Source (archive)
Luby et al. 2004 Source (archive)
Luby et al. 2005 Source (archive)
Luby et al. 2006 Source (archive)
Luby et al. 2009 Source (archive)
Sijbesma and Christoffers 2009 Source (archive)
Watson et al. 2017 Source (archive)
WHO Fact Sheet - Diarrheal disease Source (archive)
WHO Fact Sheet - Pneumonia Source (archive)
Wood et al. 2008 Source (archive)
  • 1
    • "Behaviours that encourage human contact with faecal matter include: improper disposal of faeces; children defecating on the floor; rags being used to cleanse the child after defecation; and lack of hand washing after defecation, handling faeces (including children's faeces) or cleansing the child's perineum and before handling food by caregivers and children (Pickering 2011)." Ejemot-Nwadiaro et al. 2015
    • "Most diarrheal diseases are spread by person-to-person contact or by fecal-oral routes, many times by way of contaminated hands. Handwashing can stop the spread of many diarrheal disease-causing germs, such as typhoid and cholera, by removing bacteria, parasites, and viruses from the hands." CDC Fact Sheet - Diarrheal disease
    • "There is increasing evidence (Jefferson 2005a; Jefferson 2005b; Jefferson 2005c; Jefferson 2006a; Thomas 2010) that single measures (such as the use of vaccines or antivirals) may be insufficient to interrupt the spread of influenza. However, a recent trial showed that handwashing may be effective in diminishing mortality due to respiratory disease (Luby 2005)." Jefferson et al. 2011

  • 2

    "Each year diarrhoea kills around 525 000 children under five." WHO Fact Sheet - Diarrheal disease

  • 3

    "Pneumonia accounts for 16% of all deaths of children under 5 years old, killing 920 136 children in 2015." WHO Fact Sheet - Pneumonia

  • 4

    "Washing hands with soap and water removes pathogens mechanically and may also chemically kill contaminating and colonizing flora, making hand washing more effective (Hugonnet 2000)." Ejemot-Nwadiaro et al. 2015

  • 5

    "Hand washing after defecation, or after cleaning a baby's bottom, and before preparing and eating food, can therefore reduce the risk of diarrhoea. Hand washing can be promoted through group or individual training on hygiene education, germ-health awareness, use of posters, leaflets, comic books, songs, and drama." Ejemot-Nwadiaro et al. 2015

  • 6

    "All trials used multiple hygiene interventions, except Black 1977 USA, Bowen 2004 CHN, and Pickering 2013 KEN which used only a hand washing intervention. Though Pickering 2013 KEN was a three-arm trial that investigated hand sanitizer and hand washing with soap, we only considered the arm of hand washing with soap in this Cochrane Review, as such it is categorized as a hand washing only intervention. Kotch 2003 USA assessed the impact of provision of hand washing and diapering equipment on incidence and duration of infectious illness (including diarrhoea) in both children and staff. We have described the interventions in more detail in Table 2." Ejemot-Nwadiaro et al. 2015

  • 7

    "Six trials provided soap free alongside hand hygiene promotional activities and the effect seemed to be larger in these trials than in those which did not provide soap (IRR 0.66, 95% CI 0.56 to 0.78; six trials, 11,422 participants; versus IRR 0.84, 95% CI 0.67 to 1.05; two trials, 3304 participants; Analysis 2.5)." Ejemot-Nwadiaro et al. 2015

  • 8
    • "We believe we identified all RCTs that met our inclusion criteria. We further categorised the included trials into three distinct settings in this Cochrane Review: child day-care centres or schools, community, and hospital. Although there were only a few trials included in each category, evidence favours hand washing intervention in preventing diarrhoea in all the settings. This suggests that the intervention exhibits population-wide health gains. However, most included trials in the institution subcategory were from childcare settings in high-income countries. Thus, we are not confident that this finding can be applied to schools in LMIC settings or alternative institutions. Also, only one hospital-based trial met the inclusion criteria, so evidence from this setting was limited." Ejemot-Nwadiaro et al. 2015
    • "The Handwashing Initiative consisted of marketing and strategic communication activities at multiple levels, aimed at reaching large populations. HWI delivered two levels of behavior change interventions between September 2009 and December 2010. The first intervention operated at the provincial level and consisted of mass media and direct consumer contact (DCC) activities, while the second intervention operated at the district level with additional activities delivered in communities and schools." Global Scaling Up Handwashing Project 2012

  • 9
    • "We included nine cluster-RCTs that used entire communities (generally villages, squatter settlements, or neighbourhoods, except Han 1985 MMR, which used households) as units of randomization. These trials were conducted in LMICs in Africa (Haggerty 1988 COD), Asia (Han 1985 MMR; Stanton 1985 BGD; Luby 2003a PAK; Luby 2003b PAK; Luby 2006 PAK; Langford 2007 NPL; Nicholson 2008 IND), and South America (Hartinger 2010 PER)." Ejemot-Nwadiaro et al. 2015
    • "These [school-based] trials were all conducted in high-income countries except for three trials conducted in LMICs Bowen 2004 CHN, (which was undertaken in Fujian province in China) Talaat 2008 EGY (which was conducted in Cairo, Egypt), and Pickering 2013 KEN (conducted in Nairobi, Kenya)." Ejemot-Nwadiaro et al. 2015

  • 10
    • See Tables 2 and 3 of Ejemot-Nwadiaro et al. 2015 for an overview of the activities in each program.
      • Pickering 2013 KEN: "1. Participatory discussion with teachers on germ theory and hygiene 2. UNICEF in Kenyan designed hygiene promotion kit (including posters, stickers, a classroom activity etc)."
      • Talaat 2008 EGY: "1. Larger group training sessions 2. Posters 3. Informational fliers were distributed to parents to reinforce the messages delivered at the schools 4. A special song to promote hand hygiene was developed and played regularly at schools 5. Grade specific students booklets were developed: each included a set of 12 games and fun activities that promoted hand-washing 6. The school contribute to promoting hand-washing by selecting a weekly hand hygiene champion, launching school contest for drawing, songs and drama presentations."
      • Bowen 2004 CHN: "1. Large group training 2. Posters, videotape, wall charts, games 3. Take home packs 4. Peer trainers and peer-monitoring."
      • Haggerty 1988 COD: "Large group training."
      • Han 1985 MMR: "Small group education (households)."
      • Hartinger 2010 PER: "1. Hygiene education 2. Provision of an Integrated home-based intervention package (IHIP)."
      • Langford 2007 NPL: "1. Larger meetings 2. Small group meetings: focus group discussion of 6 to 8 women 3. Posters 4. Dramas."
      • Luby 2003a PAK: "1. Large group training using slide shows, pamphlets, and video tapes; education at weekly field visits 2. Education at weekly field visits."
      • Luby 2003b PAK: "1. Large group training using slide shows, pamphlets, and video tapes 2. Education at twice-weekly visits."
      • Nicholson 2008 IND: "1. Large group training 2. Establishment of a 'Good Mums' Club 3. Environmental cues (wall hangers, danglers, etc) 4. Reward system from mothers to children (stickers, toy animals, coins, etc)."
      • Stanton 1985 BGD: "1. Small group discussion (only women or children) 2. Larger demonstrations (mixed audience) 3. Posters, games, pictorial stories, and 'flexiflans' for illustrations."
    • "A lack of good-quality evidence exists to prioritise specific handwashing promotion interventions targeted at children in LMICs. A variety of intervention methods are being employed to promote handwashing among children and not one accepted method of implementation or outcome measure has yet come to the forefront as the most effective. Due to the limited number of studies and heterogeneity of interventions, we were not able to assess the relationship between intervention effectiveness and the duration or intensity of the intervention." Watson et al. 2017

  • 11
    • “Hand washing promotion among communities in LMICs probably prevents around one-quarter of diarrhoea episodes (rate ratio 0.72, 95% CI 0.62 to 0.83; eight trials, 14,726 participants, moderate quality evidence).” Ejemot-Nwadiaro et al. 2015
    • “Overall, hand washing promotion reduced diarrhoea episodes by about a third (IRR 0.69, 95% CI 0.59 to 0.81; 11 trials, 50,044 children (Bowen 2004 CHN not included in analysis); Analysis 1.1). Most data were from high income countries (IRR 0.70, 95% CI 0.58 to 0.85; nine trials, 4664 participants; high quality evidence; Analysis 1.1), with only two trials from LMICs (IRR 0.66, 95% CI 0.43 to 0.99; two trials, 45,380 participants; low quality evidence; Analysis 1.1).” Ejemot-Nwadiaro et al. 2015
    • “We are unsure of the effect of this intervention in populations with participants above five years of age and adults, as 95% of the participants in which the primary outcome was measured were below five years of age. One trial, Talaat 2008 EGY, measured the primary outcome in participants with a mean age of eight years but did not stratify the results by age. Nicholson 2008 IND measured the primary outcome in participants of various ages (target children aged five years, children below five years of age, children aged between six to 15 years and adults) and stratified results by these independent subgroups and reported effect sizes, with no significant trend observed. Therefore the effect of the intervention may not be generalizable to all age groups.” Ejemot-Nwadiaro et al. 2015

  • 12
    • "Children younger than 5 years in households that received plain soap and handwashing promotion had a 50% lower incidence of pneumonia than controls (95% CI –65% to –34%)." Luby et al. 2005, Pg 225.
    • "Antibacterial soap. Difference vs control -45% (-64% to -26%)." Table 2, Luby et al. 2005, Pg 228.

  • 13
    • "Fourteen studies (five cluster-randomised controlled trials and nine non-randomised studies with comparison groups) from 10 low- and middle-income countries including 22,241 children at baseline and nutrition outcome data for 9,469 children provided relevant information. Study duration ranged from 6 to 60 months and all studies included children under five years of age at the time of the intervention. Studies included WASH interventions either singly or in combination. Measures of child anthropometry were collected in all 14 studies, and nine studies reported at least one of the following anthropometric indices: weight-for-height, weight-for-age or height-for-age. None of the included studies were of high methodological quality as none of the studies masked the nature of the intervention from participants." Dangour et al. 2013
    • "Meta-analysis including 4,627 children identified no evidence of an effect of WASH interventions on weight-for-age z-score (MD 0.05; 95% CI -0.01 to 0.12)." Dangour et al. 2013

  • 14
    • "Three studies reported the effect of hygiene promotion interventions, which included messages around handwashing, on STH infections." Watson et al. 2017
    • "Although there is only evidence that handwashing reduces A. lumbricoides infection, this helminth is commonly grouped together with the helminths Trichuris trichuria and hookworm, and referenced as ‘STH’." Watson et al. 2017
    • Al-Delaimy et al. 2014 was a before and after study: ”To evaluate the package, 317 children from two schools in Lipis, Pahang were screened for STH infections, treated by a 3-day course of albendazole and then followed up over the next 6 months.” Al-Delaimy et al. 2014, Pg1
    • Bieri et al. 2013 and Gyorkos et al. 2013 were cluster RCTs:
      • ”The study was an unmatched, cluster-randomized intervention trial involving 38 schools (38 clusters) and was conducted over the course of 1 school year (September 2010 through June 2011).” Bieri et al. 2013
      • ”An open-label pair-matched cluster-randomized trial was conducted in Grade 5 schoolchildren of 18 primary schools (9 intervention and 9 control) in the Peruvian Amazon.” Gyorkos et al. 2013

  • 15
    • Bieri (2013) [25] reported significant reductions in incidence of STH infections, 36 weeks after deworming, between the intervention group and control group (OR 0.50, P < 0.001), but not in the intensity of infections (OR 1.12, P = 0.12), assessed as the geometric mean number of eggs per gram of faeces. Although researchers present results as ‘all STHs’, 100% of the infections detected were A. lumbricoides and thus were amenable to the handwashing promotion intervention [25]. Gyorkos (2013) [28] showed no significant difference in A. lumbricoides infection between the intervention group and the control group 16 weeks post-deworming (adjusted OR 0.88, 95% CI: 0.57–1.34); however, the intensity of A. lumbricoides infection was significantly lower in the intervention group (adjusted incidence rate ratio 0.42, 95% CI: 0.21–0.85)." Watson et al. 2017
    • “These studies, however, may have been affected by bias due to a lack of blinding of the assessors. In one study [Gyorkos et al. 2013] that did blind the laboratory technologists assessing STH infection, and therefore was at a low risk of detection bias, no significant effect on A.lumbricoides infection was recorded [28].” Watson et al. 2017

  • 16
    • “The effect size was lower in child day-care centres or school-based trials that attempted blinding outcome assessors than in trials that did not (26% versus 33% reduction in the incidence of diarrhoea respectively). The same trend was observed for community-based trials, with 18% reduction for trials that attempted blinding of outcome assessors and 35% reduction for trials that did not attempt blinding. This suggests a possible introduction of bias in trials that did not attempt blinding. However, there were too few trials in each category to make strong conclusions.” Ejemot-Nwadiaro et al. 2015
    • “Four trials attempted blinding of outcome assessors and the benefit of hand washing appeared to be lower than in trials which did not blind outcome assessors (IRR 0.80, 95% CI 0.67 to 0.94; four trials, 3070 participants; versus IRR 0.63, 95% CI 0.48 to 0.83; four trials, 11,656 participants.” Ejemot-Nwadiaro et al. 2015

  • 17

    “In the blinding domain we acknowledged that double blinding is not possible in trials of hand washing interventions since there is no obvious placebo.” Ejemot-Nwadiaro et al. 2015

  • 18

    “We included nine cluster-RCTs that used entire communities (generally villages, squatter settlements, or neighbourhoods, except Han 1985 MMR, which used households) as units of randomization. These trials were conducted in LMICs in Africa (Haggerty 1988 COD), Asia (Han 1985 MMR; Stanton 1985 BGD; Luby 2003a PAK; Luby 2003b PAK; Luby 2006 PAK; Langford 2007 NPL; Nicholson 2008 IND), and South America (Hartinger 2010 PER).” Ejemot-Nwadiaro et al. 2015

  • 19

    "One year after baseline, overall, children in intervention sites had a reported mean of 0.85 episodes of diarrhoea, while children in control sites had 0.90 episodes (NS). Diarrhoeal incidence declined with age in both groups (Figure 2) and was lower in the third year of life among intervention compared with control children, however this was not statistically significant (P=0.09)." Haggerty et al. 1988, Pg. 1056.

  • 20

    “All participants were monitored at least every two weeks to collect data on diarrhoea episodes. This monitoring itself may have helped to improve compliance with hand washing. Only Carabin 1997 CAN attempted to investigate this effect by assessing rates in both groups compared to the pre-intervention period. They found that monitoring alone appeared to reduce the incidence of diarrhoea (IRR 0.73, 95% CI 0.54 to 0.97; Table 6), and that the intervention effect did not appear to have any benefits over and above this monitoring effect when adjusted for age and gender (IRR 0.77, 95% CI 0.51 to 1.18; Table 6) or when adjusted for age, gender, season, and baseline incidence rate in each cluster (IRR 1.10, 95% CI 0.81 to 1.50; Table 6). However, monitoring was particularly frequent (daily) in this trial.” Ejemot-Nwadiaro et al. 2015

  • 21
    • "The monitoring effect contributed to reducing the IR of diarrhea by 37% (IRR = 0.73, 95% CI = 0.54,0.97). The effect of the monitoring in reducing the IR of URTI was negligible (IRR = 0.96, 95% BCI = 0.82, 1.11)." Carabin et al. 1999, Pg 223.
    • We are unsure why Carabin et al. 1999 writes that monitoring reduced the incidence rate of diarrhea by 37% but the Incidence Rate Ratio as 0.73. We believe "37%" is likely to be an error as 0.73 is reported elsewhere in the paper (see Table 3, Carabin et al. 1999).

  • 22
    • Luby et al. 2005, the study of pneumonia, reported on the same intervention as Luby et al. 2004, which focused on diarrhea outcomes. Luby et al. 2004 had a substantially lower incidence ratio of diarrhea than any of the other eight community-based trials measuring diarrhea incidence in Ejemot-Nwadiaro et al. 2015. (Note Ejemot-Nwadiaro et al. 2015 refers to Luby et al. 2004 as "Luby 2003a PAK.") See Ejemot-Nwadiaro et al. 2015 Comparison 2, Analysis 2.1.
      • Haggarty 1988 COD: IRR:0.94 [0.85, 1.04]
      • Han 1985 MMR: IRR:0.74 [0.65, 0.85]
      • Langford 2007 NEP: IRR:0.74 [0.54, 1.01]
      • Luby 2003a PAK: IRR:0.47 [0.36, 0.61]
      • Luby 2003b PAK: IRR:0.57 [0.36, 0.89]
      • Nicholson 2008 IND: IRR:0.79 [0.50, 1.23]
      • Stanton 1985 BGD: IRR:0.75 [0.66, 0.85]

  • 23See our cost-effectiveness analysis of handwashing interventions, “sheet1,” “Handwashing promotion vs cash” row.